{"id":10873,"date":"2024-05-16T10:29:48","date_gmt":"2024-05-16T02:29:48","guid":{"rendered":"https:\/\/egonlin.com\/?p=10873"},"modified":"2025-06-12T00:03:30","modified_gmt":"2025-06-11T16:03:30","slug":"sql%e8%af%ad%e5%8f%a5","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=10873","title":{"rendered":"sql\u8bed\u53e5"},"content":{"rendered":"<h1><strong><span class=\"md-plain\">\u5e93<\/span><\/strong><\/h1>\n<h3>\u4e00 \u7cfb\u7edf\u6570\u636e\u5e93<\/h3>\n<p>information_schema\uff1a \u865a\u62df\u5e93\uff0c\u4e0d\u5360\u7528\u78c1\u76d8\u7a7a\u95f4\uff0c\u5b58\u50a8\u7684\u662f\u6570\u636e\u5e93\u542f\u52a8\u540e\u7684\u4e00\u4e9b\u53c2\u6570\uff0c\u5982\u7528\u6237\u8868\u4fe1\u606f\u3001\u5217\u4fe1\u606f\u3001\u6743\u9650\u4fe1\u606f\u3001\u5b57\u7b26\u4fe1\u606f\u7b49<br \/>\nperformance_schema\uff1a\u00a0MySQL 5.5\u5f00\u59cb\u65b0\u589e\u4e00\u4e2a\u6570\u636e\u5e93\uff1a\u4e3b\u8981\u7528\u4e8e\u6536\u96c6\u6570\u636e\u5e93\u670d\u52a1\u5668\u6027\u80fd\u53c2\u6570\uff0c\u8bb0\u5f55\u5904\u7406\u67e5\u8be2\u8bf7\u6c42\u65f6\u53d1\u751f\u7684\u5404\u79cd\u4e8b\u4ef6\u3001\u9501\u7b49\u73b0\u8c61<br \/>\nmysql\uff1a \u6388\u6743\u5e93\uff0c\u4e3b\u8981\u5b58\u50a8\u7cfb\u7edf\u7528\u6237\u7684\u6743\u9650\u4fe1\u606f<br \/>\ntest\uff1a MySQL\u6570\u636e\u5e93\u7cfb\u7edf\u81ea\u52a8\u521b\u5efa\u7684\u6d4b\u8bd5\u6570\u636e\u5e93<\/p>\n<p>&nbsp;<\/p>\n<p>information_schema\u5e93\u4e0b\u7684\u8868<\/p>\n<pre>1\u3001TABLES\u8868\uff1a\u63d0\u4f9b\u4e86\u5173\u4e8e\u6570\u636e\u5e93\u4e2d\u7684\u8868\u7684\u4fe1\u606f\r\nmysql&gt; use information_schema\r\nmysql&gt; select * from tables limit 1\\G\r\nmysql&gt; select * from tables where TABLE_NAME='city'\\G\r\n\r\ncolumns\u8868\uff1a\u63d0\u4f9b\u4e86\u5173\u4e8e\u6570\u636e\u5e93\u4e2d\u8868\u7684\u5217\u7684\u4fe1\u606f\r\nmysql&gt; select * from columns\\G\r\n\r\nSTATISTICS\u8868\uff1a\u8868\u7d22\u5f15\u7684\u4fe1\u606f\r\n\r\nCOLLATIONS\u8868\uff1a\u63d0\u4f9b\u6821\u9a8c\u89c4\u5219\u548c\u5b57\u7b26\u96c6\u5bf9\u5e94\u5173\u7cfb\r\n\r\nTable_catalog    \u6570\u636e\u8868\u767b\u8bb0\u76ee\u5f55\r\nTable_schema    \u6570\u636e\u8868\u6240\u5c5e\u7684\u6570\u636e\u5e93\u540d\r\nTable_name    \u8868\u540d\u79f0\r\nTable_type    \u8868\u7c7b\u578b[system view|base table] \u7cfb\u7edf\u8868 \uff0c\u6570\u636e\u8868\r\nEngine    \u4f7f\u7528\u7684\u6570\u636e\u5e93\u5f15\u64ce[MyISAM|CSV|InnoDB]\r\nVersion    \u7248\u672c\uff0c\u9ed8\u8ba4\u503c10\r\nRow_format    \u884c\u683c\u5f0f[Compact|Dynamic|Fixed]\r\nTable_rows    \u8868\u91cc\u6240\u5b58\u591a\u5c11\u884c\u6570\u636e\r\nAvg_row_length    \u5e73\u5747\u884c\u957f\u5ea6\r\nData_length    \u6570\u636e\u957f\u5ea6\r\nMax_data_length    \u6700\u5927\u6570\u636e\u957f\u5ea6\r\nIndex_length    \u7d22\u5f15\u957f\u5ea6\r\nData_free    \u7a7a\u95f4\u788e\u7247  \u521a\u521a\u7528\u8fc7\u7684\u6682\u65f6\u4e0d\u518d\u4f7f\u7528\r\nAuto_increment    \u505a\u81ea\u589e\u4e3b\u952e\u7684\u81ea\u52a8\u589e\u91cf\u5f53\u524d\u503c  \u53ef\u4ee5\u901a\u8fc7\u5bfc\u51fa\u518d\u5bfc\u5165\u6570\u636e\u8fdb\u884c\u91ca\u653e\r\nCreate_time    \u8868\u7684\u521b\u5efa\u65f6\u95f4\r\nUpdate_time    \u8868\u7684\u66f4\u65b0\u65f6\u95f4\r\nCheck_time    \u8868\u7684\u68c0\u67e5\u65f6\u95f4\r\nTable_collation    \u8868\u7684\u5b57\u7b26\u6821\u9a8c\u7f16\u7801\u96c6\r\nChecksum    \u6821\u9a8c\u548c\r\nCreate_options    \u521b\u5efa\u9009\u9879\r\nTable_comment    \u8868\u7684\u6ce8\u91ca\u3001\u5907\u6ce8\r\n\r\nCREATE TABLE student(gid int primary key COMMENT '\u5217\u6ce8\u91ca') COMMENT='\u8868\u6ce8\u91ca';\r\n\r\n<\/pre>\n<h3>\u4e8c \u521b\u5efa\u6570\u636e\u5e93<\/h3>\n<p>1 \u8bed\u6cd5(help create database)<\/p>\n<p>CREATE DATABASE \u6570\u636e\u5e93\u540d charset utf8;<\/p>\n<p>2 \u6570\u636e\u5e93\u547d\u540d\u89c4\u5219\uff1a<\/p>\n<pre>\u53ef\u4ee5\u7531\u5b57\u6bcd\u3001\u6570\u5b57\u3001\u4e0b\u5212\u7ebf\u3001\uff20\u3001\uff03\u3001\uff04\r\n\u533a\u5206\u5927\u5c0f\u5199\r\n\u552f\u4e00\u6027\r\n\u4e0d\u80fd\u4f7f\u7528\u5173\u952e\u5b57\u5982 create select\r\n\u4e0d\u80fd\u5355\u72ec\u4f7f\u7528\u6570\u5b57\r\n\u6700\u957f128\u4f4d\r\n<\/pre>\n<h3>\u4e09 \u6570\u636e\u5e93\u76f8\u5173\u64cd\u4f5c<\/h3>\n<div class=\"cnblogs_code\">\n<pre>1 \u67e5\u770b\u6570\u636e\u5e93\r\nshow databases;\r\nshow create database db1;\r\nselect database();\r\n\r\n2 \u9009\u62e9\u6570\u636e\u5e93\r\nUSE \u6570\u636e\u5e93\u540d\r\n\r\n3 \u5220\u9664\u6570\u636e\u5e93\r\nDROP DATABASE \u6570\u636e\u5e93\u540d;\r\n\r\n4 \u4fee\u6539\u6570\u636e\u5e93\r\nalter database db1 charset utf8;<\/pre>\n<\/div>\n<h1 class=\"md-end-block md-p\"><strong><span class=\"md-plain\">\u8868<\/span><\/strong><\/h1>\n<h3>\u4e00 \u5b58\u50a8\u5f15\u64ce\u4ecb\u7ecd<\/h3>\n<p>\u5b58\u50a8\u5f15\u64ce\u5373\u8868\u7c7b\u578b\uff0cmysql\u6839\u636e\u4e0d\u540c\u7684\u8868\u7c7b\u578b\u4f1a\u6709\u4e0d\u540c\u7684\u5904\u7406\u673a\u5236<\/p>\n<blockquote class=\"wp-embedded-content\" data-secret=\"cYkljTrFDc\"><p><a href=\"https:\/\/egonlin.com\/?p=11398\">\u5b58\u50a8\u5f15\u64ce<\/a><\/p><\/blockquote>\n<p><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"\u300a\u5b58\u50a8\u5f15\u64ce\u300b\u2014Egon\u6797\u6d77\u5cf0\" src=\"https:\/\/egonlin.com\/?p=11398&#038;embed=true#?secret=enI7WaZ808#?secret=cYkljTrFDc\" data-secret=\"cYkljTrFDc\" width=\"500\" height=\"282\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n<h3>\u4e8c \u8868\u4ecb\u7ecd<\/h3>\n<p>\u8868\u76f8\u5f53\u4e8e\u6587\u4ef6\uff0c\u8868\u4e2d\u7684\u4e00\u6761\u8bb0\u5f55\u5c31\u76f8\u5f53\u4e8e\u6587\u4ef6\u7684\u4e00\u884c\u5185\u5bb9\uff0c\u4e0d\u540c\u7684\u662f\uff0c\u8868\u4e2d\u7684\u4e00\u6761\u8bb0\u5f55\u6709\u5bf9\u5e94\u7684\u6807\u9898\uff0c\u79f0\u4e3a\u8868\u7684\u5b57\u6bb5<\/p>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/egonlin.com\/wp-content\/uploads\/2024\/05\/1036857-20170725104642078-1396398062.png'><img class=\"lazyload lazyload-style-2\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" class=\"alignnone size-full wp-image-11393\" data-original=\"https:\/\/egonlin.com\/wp-content\/uploads\/2024\/05\/1036857-20170725104642078-1396398062.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" width=\"722\" height=\"225\" \/><\/div><\/p>\n<p>id\uff0cname\uff0cqq\uff0cage\u79f0\u4e3a\u5b57\u6bb5\uff0c\u5176\u4f59\u7684\uff0c\u4e00\u884c\u5185\u5bb9\u79f0\u4e3a\u4e00\u6761\u8bb0\u5f55<\/p>\n<div>\n<h3>\u4e09 \u521b\u5efa\u8868<\/h3>\n<pre>\u8bed\u6cd5\uff1a\r\ncreate table \u8868\u540d(\r\n\u5b57\u6bb5\u540d1 \u7c7b\u578b[(\u5bbd\u5ea6) \u7ea6\u675f\u6761\u4ef6],\r\n\u5b57\u6bb5\u540d2 \u7c7b\u578b[(\u5bbd\u5ea6) \u7ea6\u675f\u6761\u4ef6],\r\n\u5b57\u6bb5\u540d3 \u7c7b\u578b[(\u5bbd\u5ea6) \u7ea6\u675f\u6761\u4ef6]\r\n);\r\n\r\n#\u6ce8\u610f\uff1a\r\n1. \u5728\u540c\u4e00\u5f20\u8868\u4e2d\uff0c\u5b57\u6bb5\u540d\u662f\u4e0d\u80fd\u76f8\u540c\r\n2. \u5bbd\u5ea6\u548c\u7ea6\u675f\u6761\u4ef6\u53ef\u9009\r\n3. \u5b57\u6bb5\u540d\u548c\u7c7b\u578b\u662f\u5fc5\u987b\u7684\r\n\r\n<\/pre>\n<\/div>\n<pre>MariaDB [(none)]&gt; create database db1 charset utf8;\r\n\r\nMariaDB [(none)]&gt; use db1;\r\n\r\nMariaDB [db1]&gt; create table t1(  \r\n    -&gt; id int, \r\n    -&gt; name varchar(50),\r\n    -&gt; sex enum('male','female'),\r\n    -&gt; age int(3)\r\n    -&gt; );\r\n\r\nMariaDB [db1]&gt; show tables; #\u67e5\u770bdb1\u5e93\u4e0b\u6240\u6709\u8868\u540d\r\n\r\nMariaDB [db1]&gt; desc t1;\r\n+-------+-----------------------+------+-----+---------+-------+\r\n| Field | Type                  | Null | Key | Default | Extra |\r\n+-------+-----------------------+------+-----+---------+-------+\r\n| id    | int(11)               | YES  |     | NULL    |       |\r\n| name  | varchar(50)           | YES  |     | NULL    |       |\r\n| sex   | enum('male','female') | YES  |     | NULL    |       |\r\n| age   | int(3)                | YES  |     | NULL    |       |\r\n+-------+-----------------------+------+-----+---------+-------+\r\n\r\nMariaDB [db1]&gt; select id,name,sex,age from t1;\r\nEmpty set (0.00 sec)\r\n\r\nMariaDB [db1]&gt; select * from t1;\r\nEmpty set (0.00 sec)\r\n\r\nMariaDB [db1]&gt; select id,name from t1;\r\nEmpty set (0.00 sec)\r\n\r\n\u5f80\u8868\u4e2d\u63d2\u5165\u6570\u636e<\/pre>\n<pre>MariaDB [db1]&gt; insert into t1 values\r\n    -&gt; (1,'egon',18,'male'),\r\n    -&gt; (2,'alex',81,'female')\r\n    -&gt; ;\r\nMariaDB [db1]&gt; select * from t1;\r\n+------+------+------+--------+\r\n| id   | name | age  | sex    |\r\n+------+------+------+--------+\r\n|    1 | egon |   18 | male   |\r\n|    2 | alex |   81 | female |\r\n+------+------+------+--------+\r\n\r\n\r\n\r\nMariaDB [db1]&gt; insert into t1(id) values \r\n    -&gt; (3),\r\n    -&gt; (4);\r\nMariaDB [db1]&gt; select * from t1;\r\n+------+------+------+--------+\r\n| id   | name | age  | sex    |\r\n+------+------+------+--------+\r\n|    1 | egon |   18 | male   |\r\n|    2 | alex |   81 | female |\r\n|    3 | NULL | NULL | NULL   |\r\n|    4 | NULL | NULL | NULL   |\r\n+------+------+------+--------+\r\n\u6ce8\u610f\u6ce8\u610f\u6ce8\u610f\uff1a\u8868\u4e2d\u7684\u6700\u540e\u4e00\u4e2a\u5b57\u6bb5\u4e0d\u8981\u52a0\u9017\u53f7\u00a0\r\n\r\n<\/pre>\n<h3>\u56db \u67e5\u770b\u8868\u7ed3\u6784<\/h3>\n<div class=\"cnblogs_code\">\n<pre>MariaDB [db1]&gt; describe t1; #\u67e5\u770b\u8868\u7ed3\u6784\uff0c\u53ef\u7b80\u5199\u4e3adesc \u8868\u540d\r\n+-------+-----------------------+------+-----+---------+-------+\r\n| Field | Type                  | Null | Key | Default | Extra |\r\n+-------+-----------------------+------+-----+---------+-------+\r\n| id    | int(11)               | YES  |     | NULL    |       |\r\n| name  | varchar(50)           | YES  |     | NULL    |       |\r\n| sex   | enum('male','female') | YES  |     | NULL    |       |\r\n| age   | int(3)                | YES  |     | NULL    |       |\r\n+-------+-----------------------+------+-----+---------+-------+\r\n\r\n\r\nMariaDB [db1]&gt; show create table t1\\G; #\u67e5\u770b\u8868\u8be6\u7ec6\u7ed3\u6784\uff0c\u53ef\u52a0\\G\r\n\r\n<\/pre>\n<h3>\u4e94 \u6570\u636e\u7c7b\u578b<\/h3>\n<blockquote class=\"wp-embedded-content\" data-secret=\"76kPBkiLrX\"><p><a href=\"https:\/\/egonlin.com\/?p=11402\">\u6570\u636e\u7c7b\u578b<\/a><\/p><\/blockquote>\n<p><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"\u300a\u6570\u636e\u7c7b\u578b\u300b\u2014Egon\u6797\u6d77\u5cf0\" src=\"https:\/\/egonlin.com\/?p=11402&#038;embed=true#?secret=YXx98nHWAz#?secret=76kPBkiLrX\" data-secret=\"76kPBkiLrX\" width=\"500\" height=\"282\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n<\/div>\n<h3>\u516d \u8868\u5b8c\u6574\u6027\u7ea6\u675f<\/h3>\n<blockquote class=\"wp-embedded-content\" data-secret=\"AkcrxmELNE\"><p><a href=\"https:\/\/egonlin.com\/?p=11410\">\u8868\u5b8c\u6574\u6027\u7ea6\u675f<\/a><\/p><\/blockquote>\n<p><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"\u300a\u8868\u5b8c\u6574\u6027\u7ea6\u675f\u300b\u2014Egon\u6797\u6d77\u5cf0\" src=\"https:\/\/egonlin.com\/?p=11410&#038;embed=true#?secret=bj2ZMrVz8r#?secret=AkcrxmELNE\" data-secret=\"AkcrxmELNE\" width=\"500\" height=\"282\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/p>\n<h3>\u4e03 \u4fee\u6539\u8868ALTER TABLE<\/h3>\n<div class=\"cnblogs_code\">\n<pre>\u8bed\u6cd5\uff1a\r\n1. \u4fee\u6539\u8868\u540d\r\n      ALTER TABLE \u8868\u540d \r\n                          RENAME \u65b0\u8868\u540d;\r\n\r\n2. \u589e\u52a0\u5b57\u6bb5\r\n      ALTER TABLE \u8868\u540d\r\n                          ADD \u5b57\u6bb5\u540d  \u6570\u636e\u7c7b\u578b [\u5b8c\u6574\u6027\u7ea6\u675f\u6761\u4ef6\u2026],\r\n                          ADD \u5b57\u6bb5\u540d  \u6570\u636e\u7c7b\u578b [\u5b8c\u6574\u6027\u7ea6\u675f\u6761\u4ef6\u2026];\r\n      ALTER TABLE \u8868\u540d\r\n                          ADD \u5b57\u6bb5\u540d  \u6570\u636e\u7c7b\u578b [\u5b8c\u6574\u6027\u7ea6\u675f\u6761\u4ef6\u2026]  FIRST;\r\n\u00a0     ALTER TABLE \u8868\u540d\r\n                          ADD \u5b57\u6bb5\u540d  \u6570\u636e\u7c7b\u578b [\u5b8c\u6574\u6027\u7ea6\u675f\u6761\u4ef6\u2026]  AFTER \u5b57\u6bb5\u540d;\r\n                            \r\n3. \u5220\u9664\u5b57\u6bb5\r\n      ALTER TABLE \u8868\u540d \r\n                          DROP \u5b57\u6bb5\u540d;\r\n\r\n4. \u4fee\u6539\u5b57\u6bb5\r\n      ALTER TABLE \u8868\u540d \r\n                          MODIFY  \u5b57\u6bb5\u540d \u6570\u636e\u7c7b\u578b [\u5b8c\u6574\u6027\u7ea6\u675f\u6761\u4ef6\u2026];\r\n      ALTER TABLE \u8868\u540d \r\n                          CHANGE \u65e7\u5b57\u6bb5\u540d \u65b0\u5b57\u6bb5\u540d \u65e7\u6570\u636e\u7c7b\u578b [\u5b8c\u6574\u6027\u7ea6\u675f\u6761\u4ef6\u2026];\r\n      ALTER TABLE \u8868\u540d \r\n                          CHANGE \u65e7\u5b57\u6bb5\u540d \u65b0\u5b57\u6bb5\u540d \u65b0\u6570\u636e\u7c7b\u578b [\u5b8c\u6574\u6027\u7ea6\u675f\u6761\u4ef6\u2026];\r\n\r\n\r\n\r\n<\/pre>\n<pre>\u793a\u4f8b\uff1a\r\n1. \u4fee\u6539\u5b58\u50a8\u5f15\u64ce\r\nmysql&gt; alter table service \r\n    -&gt; engine=innodb;\r\n\r\n2. \u6dfb\u52a0\u5b57\u6bb5\r\nmysql&gt; alter table student10\r\n    -&gt; add name varchar(20) not null,\r\n    -&gt; add age int(3) not null default 22;\r\n    \r\nmysql&gt; alter table student10\r\n    -&gt; add stu_num varchar(10) not null after name;                \/\/\u6dfb\u52a0name\u5b57\u6bb5\u4e4b\u540e\r\n\r\nmysql&gt; alter table student10                        \r\n    -&gt; add sex enum('male','female') default 'male' first;          \/\/\u6dfb\u52a0\u5230\u6700\u524d\u9762\r\n\r\n3. \u5220\u9664\u5b57\u6bb5\r\nmysql&gt; alter table student10\r\n    -&gt; drop sex;\r\n\r\nmysql&gt; alter table service\r\n    -&gt; drop mac;\r\n\r\n4. \u4fee\u6539\u5b57\u6bb5\u7c7b\u578bmodify\r\nmysql&gt; alter table student10\r\n    -&gt; modify age int(3);\r\nmysql&gt; alter table student10\r\n    -&gt; modify id int(11) not null primary key auto_increment;    \/\/\u4fee\u6539\u4e3a\u4e3b\u952e\r\n\r\n5. \u589e\u52a0\u7ea6\u675f\uff08\u9488\u5bf9\u5df2\u6709\u7684\u4e3b\u952e\u589e\u52a0auto_increment\uff09\r\nmysql&gt; alter table student10 modify id int(11) not null primary key auto_increment;\r\nERROR 1068 (42000): Multiple primary key defined\r\n\r\nmysql&gt; alter table student10 modify id int(11) not null auto_increment;\r\nQuery OK, 0 rows affected (0.01 sec)\r\nRecords: 0  Duplicates: 0  Warnings: 0\r\n\r\n6. \u5bf9\u5df2\u7ecf\u5b58\u5728\u7684\u8868\u589e\u52a0\u590d\u5408\u4e3b\u952e\r\nmysql&gt; alter table service2\r\n    -&gt; add primary key(host_ip,port);        \r\n\r\n7. \u589e\u52a0\u4e3b\u952e\r\nmysql&gt; alter table student1\r\n    -&gt; modify name varchar(10) not null primary key;\r\n\r\n8. \u589e\u52a0\u4e3b\u952e\u548c\u81ea\u52a8\u589e\u957f\r\nmysql&gt; alter table student1\r\n    -&gt; modify id int not null primary key auto_increment;\r\n\r\n9. \u5220\u9664\u4e3b\u952e\r\na. \u5220\u9664\u81ea\u589e\u7ea6\u675f\r\nmysql&gt; alter table student10 modify id int(11) not null; \r\n\r\nb. \u5220\u9664\u4e3b\u952e\r\nmysql&gt; alter table student10                                 \r\n    -&gt; drop primary key;\r\n\r\n\r\n<\/pre>\n<\/div>\n<h3>\u516b \u590d\u5236\u8868<\/h3>\n<div class=\"cnblogs_code\">\n<pre>\u590d\u5236\u8868\u7ed3\u6784\uff0b\u8bb0\u5f55 \uff08key\u4e0d\u4f1a\u590d\u5236: \u4e3b\u952e\u3001\u5916\u952e\u548c\u7d22\u5f15\uff09\r\nmysql&gt; create table new_service select * from service;\r\n\r\n\u53ea\u590d\u5236\u8868\u7ed3\u6784\r\nmysql&gt; select * from service where 1=2;        \/\/\u6761\u4ef6\u4e3a\u5047\uff0c\u67e5\u4e0d\u5230\u4efb\u4f55\u8bb0\u5f55\r\nEmpty set (0.00 sec)\r\nmysql&gt; create table new1_service select * from service where 1=2;  \r\nQuery OK, 0 rows affected (0.00 sec)\r\nRecords: 0  Duplicates: 0  Warnings: 0\r\n\r\nmysql&gt; create table t4 like employees;<\/pre>\n<\/div>\n<h3>\u4e5d \u5220\u9664\u8868<\/h3>\n<div class=\"cnblogs_code\">\n<pre>DROP TABLE \u8868\u540d;<\/pre>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"cnblogs_code\">\n<pre><\/pre>\n<\/div>\n<h1 class=\"md-end-block md-p\"><strong><span class=\"md-plain\">\u8bb0\u5f55<\/span><\/strong><\/h1>\n<h3>\u4e00 \u4ecb\u7ecd<\/h3>\n<p>MySQL\u6570\u636e\u64cd\u4f5c\uff1a DML<\/p>\n<p>========================================================<\/p>\n<p>\u5728MySQL\u7ba1\u7406\u8f6f\u4ef6\u4e2d\uff0c\u53ef\u4ee5\u901a\u8fc7SQL\u8bed\u53e5\u4e2d\u7684DML\u8bed\u8a00\u6765\u5b9e\u73b0\u6570\u636e\u7684\u64cd\u4f5c\uff0c\u5305\u62ec<\/p>\n<ol>\n<li><em>\u4f7f\u7528INSERT\u5b9e\u73b0\u6570\u636e\u7684\u63d2\u5165<\/em><\/li>\n<li><em>UPDATE\u5b9e\u73b0\u6570\u636e\u7684\u66f4\u65b0<\/em><\/li>\n<li><em id=\"__mceDel\">\u4f7f\u7528DELETE\u5b9e\u73b0\u6570\u636e\u7684\u5220\u9664<\/em><\/li>\n<li><em id=\"__mceDel\">\u4f7f\u7528SELECT\u67e5\u8be2\u6570\u636e\u4ee5\u53ca\u3002<\/em><\/li>\n<\/ol>\n<p><em>========================================================<\/em><\/p>\n<p>\u672c\u8282\u5185\u5bb9\u5305\u62ec\uff1a<\/p>\n<p>\u63d2\u5165\u6570\u636e<br \/>\n\u66f4\u65b0\u6570\u636e<br \/>\n\u5220\u9664\u6570\u636e<br \/>\n\u67e5\u8be2\u6570\u636e<\/p>\n<h3>\u4e8c \u63d2\u5165\u6570\u636eINSERT<\/h3>\n<div class=\"cnblogs_code\">\n<pre>1. \u63d2\u5165\u5b8c\u6574\u6570\u636e\uff08\u987a\u5e8f\u63d2\u5165\uff09\r\n    \u8bed\u6cd5\u4e00\uff1a\r\n    INSERT INTO \u8868\u540d(\u5b57\u6bb51,\u5b57\u6bb52,\u5b57\u6bb53\u2026\u5b57\u6bb5n) VALUES(\u503c1,\u503c2,\u503c3\u2026\u503cn);\r\n\r\n    \u8bed\u6cd5\u4e8c\uff1a\r\n    INSERT INTO \u8868\u540d VALUES (\u503c1,\u503c2,\u503c3\u2026\u503cn);\r\n\r\n2. \u6307\u5b9a\u5b57\u6bb5\u63d2\u5165\u6570\u636e\r\n    \u8bed\u6cd5\uff1a\r\n    INSERT INTO \u8868\u540d(\u5b57\u6bb51,\u5b57\u6bb52,\u5b57\u6bb53\u2026) VALUES (\u503c1,\u503c2,\u503c3\u2026);\r\n\r\n3. \u63d2\u5165\u591a\u6761\u8bb0\u5f55\r\n    \u8bed\u6cd5\uff1a\r\n    INSERT INTO \u8868\u540d VALUES\r\n        (\u503c1,\u503c2,\u503c3\u2026\u503cn),\r\n        (\u503c1,\u503c2,\u503c3\u2026\u503cn),\r\n        (\u503c1,\u503c2,\u503c3\u2026\u503cn);\r\n        \r\n4. \u63d2\u5165\u67e5\u8be2\u7ed3\u679c\r\n    \u8bed\u6cd5\uff1a\r\n    INSERT INTO \u8868\u540d(\u5b57\u6bb51,\u5b57\u6bb52,\u5b57\u6bb53\u2026\u5b57\u6bb5n) \r\n                    SELECT (\u5b57\u6bb51,\u5b57\u6bb52,\u5b57\u6bb53\u2026\u5b57\u6bb5n) FROM \u88682\r\n                    WHERE \u2026;\r\n<div id=\"rml_readmorelogin_placeholder\" style=\"position:relative;\"><div id=\"rml_fade_content\" style=\"position: absolute;\r\ntop:-10em;\r\nwidth:100%;\r\nheight:10em;\r\nbackground: -webkit-linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\r\nbackground-image: -moz-linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\r\nbackground-image: -o-linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\r\nbackground-image: linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\r\nbackground-image: -ms-linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\"><\/div><div class=\"wpf-controller aru_rml_from_in_post\" style=\"background-color:#eeeeee;border:5px solid #cce6ff;\" id=\"ARU_ReadMoreLogin_ReadMoreLoginController\"><h2 id=\"Header\">\u67e5\u770b\u66f4\u591a<\/h2><div id=\"Message\"><p>\u8054\u7cfb\u7ba1\u7406\u5458\u5fae\u4fe1tutu19192010\uff0c\u6ce8\u518c\u8d26\u53f7<\/p>\n<\/div><div id=\"StatusBarHeader\"><\/div><form id=\"ARU_ReadMoreLogin_ReadMoreLoginController\"><input name=\"post_id\" value=\"10873\" type=\"hidden\"\/><input name=\"_init_callback\" value=\"InitLogin\" type=\"hidden\"\/><input name=\"post_id\" value=\"10873\" type=\"hidden\"\/><input name=\"rt_ype\" value=\"1\" type=\"hidden\"\/><input name=\"nonce\" value=\"dea9c76afc\" type=\"hidden\"\/><input name=\"_wpnonce\" value=\"2d1dcda414\" type=\"hidden\"\/><input name=\"_controller\" value=\"ARU_ReadMoreLogin\\ReadMoreLoginController\" type=\"hidden\"\/><input name=\"_proxy_controller\" value=\"ARU_ReadMoreLogin\\ReadMoreLoginController\" type=\"hidden\"\/><input name=\"_view\" value=\"ARU_ReadMoreLogin\\ReadMoreLoginView\" type=\"hidden\"\/><table class=\"wpf-table-placeholder\"><tbody class=\"wpf-table-placeholder\"><tr class=\"wpf-table-placeholder\"><td class=\"wpf-table-placeholder-input\" width=\"400px\"><table class=\"wpf-table-placeholder\"><tbody class=\"wpf-table-placeholder\"><tr class=\"wpf-table-placeholder\"><th class=\"wpf-table-placeholder-input\"><label class=\"wpf-label\">Username:<\/label><\/th><\/tr><tr class=\"wpf-table-placeholder\"><td class=\"wpf-table-placeholder-input\"><input class=\"regular-text text_input\" name=\"username\" value=\"\" type=\"text\"\/><\/td><\/tr><tr class=\"wpf-table-placeholder\"><th class=\"wpf-table-placeholder-input\"><label class=\"wpf-label\">Password:<\/label><\/th><\/tr><tr class=\"wpf-table-placeholder\"><td class=\"wpf-table-placeholder-input\"><input class=\"regular-text text_input\" name=\"password\" value=\"\" type=\"password\"\/><\/td><\/tr><\/tbody><\/table><p class=\"wpf-table-placeholder submit\"><button class=\"wp_plugin_framework_ajax_button\" type=\"button\" style=\"background-color:#4D90FE;;color:#ffffff;;border:1px solid #3079ed;\" name=\"_event\" value=\"ButtonLogin\">Log in<\/button><\/p><\/td><td class=\"wpf-table-placeholder-input\"><\/td><\/tr><\/tbody><\/table><\/form><div id=\"ButtonStartRegister\"><a href=\"https:\/\/egonlin.com\/wp-login.php?action=register\">Register<\/a><\/div><div id=\"Link1\"><a href=\"https:\/\/egonlin.com\/wp-login.php?action=lostpassword\">Forgotten username or password?<\/a><\/div><div id=\"StatusBarFooter\"><\/div><\/div><\/div><div id=aru_remaining_content><\/div>","protected":false},"excerpt":{"rendered":"<p>\u5e93 \u4e00 \u7cfb\u7edf\u6570\u636e\u5e93 information_schema\uff1a \u865a\u62df\u5e93\uff0c\u4e0d\u5360\u7528\u78c1\u76d8\u7a7a\u95f4\uff0c\u5b58\u50a8\u7684\u662f\u6570\u636e\u5e93\u542f\u52a8\u540e\u7684\u4e00\u4e9b [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":6748,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[80],"tags":[],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/10873"}],"collection":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10873"}],"version-history":[{"count":34,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/10873\/revisions"}],"predecessor-version":[{"id":11424,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/10873\/revisions\/11424"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/media\/6748"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10873"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10873"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10873"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}